[U-Boot] [ppc] qemu-ppce500 howto

[Alexander Graf]

On 25.05.2014, at 13:33, Alon Bar-Lev <alon.barlev at gmail.com> wrote:

> On Sun, May 25, 2014 at 2:16 PM, Alexander Graf <agraf at suse.de> wrote:
>> 
>> On 25.05.2014, at 13:10, Alon Bar-Lev <alon.barlev at gmail.com> wrote:
>> 
>>> On Sun, May 25, 2014 at 1:08 PM, Alexander Graf <agraf at suse.de> wrote:
>>>> 
>>>> 
>>>> On 24.05.14 09:23, Alon Bar-Lev wrote:
>>>>> 
>>>>> On Thu, May 22, 2014 at 12:04 PM, Alexander Graf <agraf at suse.de> wrote:
>>>>>> 
>>>>>> 
>>>>>> On 22.05.14 09:52, Alon Bar-Lev wrote:
>>>>>>> 
>>>>>>> Hi,
>>>>>>> 
>>>>>>> Trying to run the qemu-ppce500 within qemu. I am using -bios u-boot.bin and no luck, I get live signal.
>>>>>>> 
>>>>>>> I am using latest u-boot master and qemu master.
>>>>>>> 
>>>>>>> Command:
>>>>>>> $ ./qemu-system-ppc -M ppce500 -nographic -bios u-boot.bin
>>>>>>> 
>>>>>>> Tried to load u-boot as well, same.
>>>>>> 
>>>>>> 
>>>>>> Yes, that command should work with the right patches :). Unfortunately they are not in master yet, but instead waiting in my queue:
>>>>>> 
>>>>>>  https://github.com/agraf/qemu
>>>>>> 
>>>>>> Please give things a try with the ppc-next branch in there. That should get things working for you.
>>>>>> 
>>>>> WORKING! thanks!
>>>>> 
>>>>> Is there any support for flush and/or mtd for this target (-drive
>>>>> if=pflash, -mtdblock)?
>>>> 
>>>> 
>>>> I haven't implemented pflash yet, sorry. Do you need the flash device for configuration storage or as backing storage for your kernel?
>>>> 
>>> 
>>> Well, I wish both... :)
>>> 
>>> boot qemu as if it were a target....
>>> 
>>> 1. put u-boot on pflash, and boot from it.
>>> 2. have backing storage for kernel (can be mtd).
>>> 3. have data partition (can be mtd).
>>> 
>>> we can skip (1) as -bios is good enough... but for (2), (3) I do not
>> 
>> For (2) you can use the -kernel option. It should make the payload's physical address available through an environment variable. If it's a uImage, it will get loaded automatically.
>> For (3) you can use all the emulated block storage options QEMU provides, such as virtio-pci or ahci.
>> 
> 
> ahci works, thanks I did not know this notation is possible:
> 
> qemu .... \
> -device ahci,id=ahci0 \
> -drive  if=none,file=/tmp/img1,format=raw,id=drive-sata0-0-0 \
> -device ide-drive,bus=ahci0.0,drive=drive-sata0-0-0,id=sata0-0-0
> 
> Now I see mass storage device on pci bus.
> 
> Thanks for the reference!
> 
> Now, I am almost sure we are missing commands within the u-boot
> configuration to allow accessing the ide/scsi, fsinfo and friends.

Yes, the only device that I managed to get working was the emulated e1000 adapter. There are no virtio drivers in u-boot and the AHCI driver didn't compile for me :).

> 
>>> see solution but have either mtd or other block device support... is
>>> that possible?
>> 
>> It's definitely possible, yes :). I simply didn't implement any mtd device emulation so far in the QEMU machine model. But patches are definitely welcome!
>> 
> 
> I would have glad to... However, unfortunately, I am not at that level... :(

I'll put it on my todo list, but don't expect me to get around to it very soon :)


Alex